Carillon



E. V. SUNDT June 16, 1942.

CARILLQN Filed July 15, 1940 .3 Sheets-Sheet 1 I Zmnentor [alumniYJvrzcZi June 16, 1942. E. v. SUNDT 2,236,537

CARILLON Filed quly 15, 1940 5 Sheets-Sheet 3 Enventor Edward If Jvn(Zij Patented June 16, 1942 1 UNITED I STATES PATENT OFFICIE ApplicationJuly 15, 8844:2210. 345,659

14- Claims.

This invention relates to musical instruments generally. Moreparticularly this invention relates to a method and means for tuninmusical instruments and to a carillon of the amplified type wherein thevibrations from suitably actuated chimes are amplified and broadcast byradio or direct from church belfries or other places of mounting throughthe medium of loud speakers.

An object of this invention is to provide an,

novel form of vibration pick-up for receiving or picking up thevibrations produced in the chimes or other vibrating instruments ormembers and blending or mixing these vibrations in suitable circuitssuch as the circuits of an amplifier to produce desired musical effectswhich may be impressed upon a loud speaker system directly ortransmitted over an electrical or radio circuit.

Another object of this invention is to provide a carillon employingtubular chimes of an improved type which may be tuned without difficultyby means of an adjustable plug.

Still another object of this invention is to provide an improved type ofchime solenoid action which is quiet in operation, is highly wearresistant and will operate over a long period of time without attentionor lubrication.

A further object of this invention is to provide a double touch keyboardto the carillon so that the musician playing the carillon can controlthe music produced.

Still another object of this invention is to provide an arrangement fortuning percussion type musical instruments in which vibrations from themusical instrument are picked up electrically and fed back to thevibrating member as amplified acoustic vibrations to maintain thevibrating member in vibration long enough so that the frequency and waveform thereof may be checked, observed and compared to a standard.

Other and further objects of this invention will be apparent to. thOSeskilled in the art to which it relates from the following specificationand the claims.

In accordance with this invention I provide an amplified carillon whichhas many basic advantages over that of the outdoor un-amplifiedcarillons heretofore used almost exclusively, in that tubular chimes canbe used with great carrying power and in this way secure greater purityof tone than is possible with the conventional bells. It is we-ll'knownthat the conventional bell has harmonics, or overtones, that are not intune with their fundamental. This is not true on correctly constructedtubular chimes. Also, the accuracy of tuning of a tubular chime is veryclose when done according to the process of tuning I will describelater. Also, the ease of playing an amplified carillon of the type heredisclosed permits musical effects and performance of compositions notpossible. where the bells of the carillon are struck manually by themusiobvious that tubular chimes need not necessarily be used since rodsor spiral chimes, bars, and other instruments of a percussion nature,may also be used and amplified. Furthermore, my process of tuning is notlimited to tubular chimes, but embraces all percussion instruments.

Further details of this invention are set forth in the specification andthe drawings in which, briefly:

I Fig. 1 is a schematic wiring diagram of the amplified carillon;

Fig. 2 is a cross-section of one of the tubular chimes;

Fig. 3 is a perspective view of the magnetic pick-up and springsuspension;

Fig. 4 is an end view of one of the tubular chimes showing the positionof the magnetic pick-up;

Fig. 5 is a detail view of the chime solenoid action including thestriker and the damper;

Fig. 6 illustrates details of one of the double touch keys of thekeyboard;

Fig. '7 is a schematic circuit diagram of the chime tuning circuit andFigs. 8, 9 and 10 illustrate time delay circuits connected to the chimepick-up device and amplifier tube.

Referring to the drawings in detail reference numeral ill designates thetubular chimes used in this amplified carillon; these are\in generalconventional, but have added to them a special magnetic pick-up II whichis used to pick-up the relatively weak fundamental note of these chimes.This fundamental note is amplified separately by means of a vacuum tubeamplifier l2,

' the input of which is coupled to the magnetic pick-up by means of thetransformer I3. The primary of this transformer is connected to themagnetic pick-up through the contacts II of the double touch key I5which is-also provided with additional contacts ii for connecting thestriker solenoid ll to the source of current supply i8. The contacts iiiare closed when the key is depressed, energizing the circuit of thestriker soleby the solenoid I! so that the chime is free to vibrate.

A whole series of tubular chimes corresponding to zone or more octavesof the chromatic scale is employed or if desired the chimes may bearranged in accordance with any other predetermined scale or in a seriesof chords. In each case each of the chimes is provided with a strikersolenoid, a damper raising solenoid anda magnetic pick-up.

The striker solenoid I1 is shown positioned adiacent to the supportedend of the chime I and this being the case the predominating tonegenerated by the chime will be the second harmonic.

The second harmonic, or "strike note as-it is often called. is picked upby one or more microphones 20. although other pickups may also be used,if desired, to secure this harmonic. The microphone 2|) is connected tothe input of the amplifier tube 2| through a suitable coupling circuitsuch as a transformer or a resistance .and a condenser as isconventional in the art. Likewise the magnetic pick-up device Il may beconnected to the input of the amplifier tube l2 through coupling devicessuch as resistors and condensers instead of the transformer l3. In caseswhere the microphone 20 is of the correct impedance to match theamplifier tube employed this microphone may be connected directly to thegrid of this tube without the use of any other coupling circuits formatching the impedance of the microphone to that of the tube. However incases where a plurality of microphones is employed a coupling networkmay be desirable. Furthermore amplifier tubes other than the threeelectrode types illustrated may be employed for the tubes l2 and 2|particularly where high ampliflcation is desired in these tubes. Theanodes of the tubes l2 and 2| are connected to a suitable source ofanode current supply through the plate resistors 22 and 23 respectively.The anode circuits of these amplifier tubes l2 and 2| are coupledthrough coupling condensers and volume control resistors consisting ofthe coupling condenser 24 and variable resistor 28 for the tube l2 andthe coupling condenser 25 and variable resistor 21 for the tube 2l,'tothe input conductor 29 connected to the input of the power amplifier 30.The volume control resistors 21 and 28 are arranged to be controlled bysuitable pedals which may be arranged to be operated by hand, knee orfoot of the musician playing the instrument and are for the purpose ofcontrolling the energy derived from the pick-ups II and 20 to beimpressed upon the power amplifier 30 and loudspeakers 3 I connected tothe output thereof.

It will be observed that the magnetic pick-ups I I are not connected tothe input of the amplifier l2 simultaneously as the striker'solenoid I1is energized through the contact l6 of the key l but that this key mustbe still further depressed so that it not only closes the contacts I6but also the contacts l4 which close the circuit of the magnetic pick-upand the primary of the transformer l3. This feature of the inventionwillbe more readily appreciated from the description of the construction ofthe key and its associated contacts. 7

The magnetic pick-up l,l consists of an insulated winding of amultiplicity of turns of relatively small wire wound around a smallpermanent magnet. This is supported by means of elastic members 32 whichmay be in the form of springs, rubber, synthetic rubber and the like, inthe short ring member 33 adjacent to the iron I the tube.

armature 34 which is rigidly fastened in said ring. It is important thatthe magnetic pick-up I I be suspended freely by an elastic means whichwill perm't the chime tube In to vibrate without a, damping efiect uponit, reacted from the pickup itself. While I show the magnetic pick-up inFig. 2 as located at the extreme end, its location may be in any part ofthe tube. And the particular harmonic that it picks up is determined byits position along the length of the tube. Thus, several pick-ups may beused, if desired, toblend various harmonics.

In'Figure 2 is also shown a construction which facilitatesthe tuning ofthe chime. This consists of an iron plug35 mounted inside of one end ofthe chime and a solid screw 36 threaded inside of said iron plug so asto be capable ofbeing screwed in or out to give the efiect'of shorteningor lengthening, respectively, the entire chime. In this way the chimecan be tuned more quickly and easily than was possible with the oldmethod of filing off part of the chime until the correct tuning wasobtained. It also has the advantage that in the event the chime is tunedtoo sharp, the plug can always be unscrewed a small distance to producethe same effect as lengthening With the other method of tuning, if thechime was ever tuned too sharp, it would then have to be cut off to thenext semi-tone, since length could not be added very well.

A very important feature in the operation of my carillon is the actionused to strike the chime.

shown in detail in Fig. 5. These actions must be quiet, highlywear-resistant, and must operate over long periods of time withoutattention or lubrication. The action used in the carillon here disclosedis actuated by a solenoid winding ll enclosed in a thin iron case 38 andpositioned between the poles of an iron yoke 39 which forms,

part of the magnetic circuit. The iron striker 40 rides inside of thegraphite bronze sleeve 4!. In order to provide lubrication withoutoiling,

I have made the sleeves M of these striker solenoids from a compositiongraphite and bronze material in which the graphite and the bronze aremixed and then placed under intense hydraulic pressure, so that a hard,homogeneous bearing material is formed. As the sleeve wears, thegraphite becomes exposed and also furnishes a well lubricated surface,which does not require oil. A bronze sleeve with graphited grooves mayalso be used. The sleeve 4| is positioned inside of the brass sleeve 42and these two sleeves pass through the center of the solenoid winding. Acoil spring 43 is attached to the end 44 of the iron striker 40 and tothe cap 45 attached to the ends of the sleeves so as to maintain thesolenoid armature or striker normally somewhat displaced from the centerof the winding. when the solenoid winding is energized by closing thecontacts IS the magnetic lines of force set-up act on the armature 40and accelerate it toward the center of the winding. However thisacceleration is great enough to cause the armature to shoot out of thewinding and hit the chime tube i0, mounted adjacent thereto, with theleather tip 46 setting the chime into vibration. The spring 43 functionsto bring the armature back to its normal position.

The damper mechanism including the solenoid bronze sleeve 48 and brasssleeve 49 is mounted so that the lead weight 50 thereof normally pressesthe felt 5| against an end of the respective chime tube to damp thevibration of the tube I ploying one or more tubes.

except when such vibration is desired. The lead weight 58 is attached tothe armature I! by means of abolt 52 and the felt is cemented to a faceof the lead weight. Inasmuch as the tubes III are supported from endsthereof by suspension cords 58, as shown in Figs. 1 and 2, it isconvenient to mount the damper mechanism at the top of each chimebetween these cords so that the weight 58 rests on the chime except whenthe winding is energized. 1 4

A further feature of this carillon is the'doubletouch keyboard wherebythe musician can control the music .picked up by the microphones 28 andthe music obtained by the magnetic pick-ups I I, separately. This isaccomplishedby a doubletouch keyboard employing a plurality of keys,such as, key l5 pivotally mounted on the pin." and provided with acontact actuating member 54 screwed into the far end of the key asillustrated in Fig. 6 are employed. The member 54 engages the contactspring 55 when the key is depressed and forces the lower contact IE toengage the upper contact it which is supported by the spring 58. Thesesprings 55 and 58 are supported upon an insulation block 58 and abovethe spring 58 is positioned another insulation block 55. The contacts I!are attached to the springs GI and 62 which are spaced by the insulatorBI) and supported on the insulator 59. By this construction, when thekey I5 is depressed only part way by a light touch, the circuit betweencontacts I6 is closed to energize the striking solenoid l1, andsimultaneously the damper 505I is lifted from the chime tube by thesolenoid l9. The sound produced by this action is picked up by one ormore microphones 20, and the volume produced is controlled by a separatepedal volume control 21- connected to the output of the amplifier 2|em.-

As the key is further depressed contact is made between contacts I whichresults in closing the circuit through one or more magnetic or similarpick-ups ll used on the particular chime tube struck. The output ofthese pick-ups is amplified by the amplifier I2 consisting of one ormore tubes and the output of this amplifier is controlled by anotherpedal volume control 28. the musician to blend the two -types of musicsecured from the instrument in any proportion with respect to volume,and he can fade out one while increasing the other to secure distanceeffects, echo efiects, or use the one as an accompaniment to the other.

A further feature of this action is a time delay introduced in themagnetic pick-up circuit to avoid a sharp interruption of the low belltone sounds secured through the magnetic pick-ups. Several methods maybe used and the most practical ones I have illustrated in Figs. 8, 9-and10.

In Fig.8 time delay action is obtained through the use of a relay I8,the contacts 11 of which are connected between the pick-up II and theprimary of the transformer I3. A condenser 19 of relatively largecapacity, for example, 1000 mid, for 4 seconds delay action, is shuntedacross a relay coil which, after it is charged by the closing of thekeyboard contacts l4, connected to the conductors GI and 62, tendsto-hold the relay closed for a time depending upon the size of thecondenser, after the musician has released the key.

In the form of time delay circuit shown in Fig, 9 the key contacts I areconnected through the conductors GI and 81 to the grid bias resistor 15and cathode of the tube It, respectively,

This arrangement allows- When the key contacts I4 are closed grid biaspotential is applied through the resistor 15 to the grid of the tube sothat the tube functions as an amplifier and at the same time the cathodeof the tube is grounded to the chassis or frame of the amplifier towhich the negative terminal of the anode current supply and the resistor15 are connected. In this way a charge is supplied to the condenser 15and when the key circuit 8 l82 is opened this charge is applied betweenthe grid and cathode until it leaks oflf or is dissipated through thecondenser dielectric. A separate battery such as, battery 88 shown inFig. 10, may be provided for charging the time delay condenser. When thekey contacts I! are closed the battery 83 charges the condenser 8|connected to the grid of the tube l2.. This'battery 83 may be used asthe grid bias battery during 7 this same timeto bias the tube and causeit to act as an amplifier. When the key contacts [4 are opened thecharge of the condenseral' furnishes the bias potential for 1, 2, 3, 4or more seconds depending upon the size of the condenser and the rate ofleakage through the resistor 82 and condenser, Where the condenser hasthe proper leakage the resistor 82 is not necessary although it isdesirable to permit adjustment of the time delay action. Furthermore theresistor 15 and condenser 16 may be eliminated in this case since thecondenser 8|, resistor 82 and battery 83 furnish the proper biaspotential. However where it is desirable to alter the amplifyingcharacteristics of the tube l2 after the key contacts M are opened thegrid bias circuit may be divided into two sections as shown.

One of the most important factors in the production of this carillon isthe process of tuning. It has always been very diiiicult to play severalbells, or chimes simultaneously for the reason that the sound of aninstrument of this type is particularly rich in the high harmonics. Whentuning by car, it is, diflicult, if not impossible, to tune closer thanone or two 'cycles. And even expert tuners, when they get this close,can not differentiate between a high or low pitch, i. 0., they may beable to tell the pitch is off one or two cycles per second, but they cannot tell whether, the pitch is sharp or fiat. When two chimes are out oftune by only one cycle in their fundamental, itfollows that theirharmonics are going to be out of tune by the increased ratio of theirfrequencies with respect to the fundamentaland this clash of higherfrequencies tends to cause the out-of-tune sound so often heard in hellcarillons.

By my process I use conventional cathode ray oscillograph circuits to.tune the chimes within limits as close as one-fiftieth of one cycle;and the carillon resulting from a combination of such closely tunedchimes is capable of musical effects that are very beautiful andpleasing indeed. The basic diagram of the tuning circuit used is shownin Fig. 7.

Even in using an oscillograph, or other frequency sensitive instrument,it is almost impossible to tune closely if the instruments are struck inthe conventional manner. The reason for this is that the volume of soundrises to a peak immediately after the chime is struck, and then diesdown quite rapidly, four orfive seconds as a matter of fact. This timeis too short to permit a close observation and comparison of frequenciesin the measuring instruments. In my process, however, I make thevibration of the chime self-sustaining, and by this method I am tubeamplifier 65 consisting of one or more amplifler tubes coupled bysuitable circuits, and the output of this amplifier is fed into aspeaker 64 which is located relatively close to the chime. The energy ofthe sound waves striking the chime from the speaker 64 are sufllcient tore-energize itso that the chime continues to vibrate at its naturalfrequency. Furthermore, by shifting the position of the pick-up 83 alongthe length of the chime, I am able to pick off various harmonics whosefrequencies are direct multiples of the fundamental resonant frequencyof the chime. And in this way even more accurate tuning can beaccomplished, since I can pick off a harmonic eight times (for instance)the ire-- quency of the fundamental and by tuning them to a limit of ofa cycle, the actual accuracy of 1 the fundamental would, therefore, beoneeighth of that, or /150 of a cycle. Other means than magnetic ofpicking off the fundamental or harmonic vibrations may be used withexcellentv ing photo-electric cells, and methods where the audiofrequencies produced by the chime tube are used to modulate a radiofrequency carrier wave. The important feature of all of these methods,however; is to make the chime tube self-excited for the purpose oftuning.

Inasmuch as it is very difficult to tune by ear and to tell whether theinstrument being tuned. is sharp or flat with respect to the standardwhen they become close to unison, I use a cathode ray oscillograph 56 toindicate the relative frequencies. Two methods of doing this may beused. In one, the standard frequency from an oscillator such as thetuning fork oscillator Ill is applied to one set of the cathode ray tubedeflector plates and the frequency under observation, that is part ofthe output of the amplifier 55, is applied to the other set of cathoderay tube deflector plates, resulting in the conventional Lissajousfigures. Thus, where the frequencies are in unison, an ellipse is formedon the cathode ray tube screen; with double frequency a figure 8, etc.In the other method, the frequency under observation is applied to thevertical deflecting plates and the standard frequency is used to controlthe sweep .of the horizontal deflecting plates.

By this method the frequency under observation appears standstill on thecathode ray tube screen when the frequencies are in perfect 'unison.

When the frequency under observation is fiat 'amplifier 85 and thedeflector plates of the 'be the most practical.

ters, high or low pass filters may be connected between the loud speaker64 and the amplifier so that as the pick-up 63 is moved along the tubethe desired selected harmonic may be given preference. Likewise suchselective ,circuits may be interposed in the connections between thecathode ray oscillograyh B8.

As a standard I found a self-excited tuning coil I! of the tuning forkoscillator tube 12, to

The signal from this tuning fork oscillator is fed into the amplifierportion of the apparatus ll consisting of one or more tubes lit-ll andthen to the cathode ray oscillograph tube. Where the tuning forkoscillator is used to control the sweep frequency of the cathode rayoscillograph, for example, as in the second tuning method given, asuitable saw-tooth oscillator controlled by the tuning fork oscillatormay be incorporated in the apparatus ll. Tuning forks calibrated to anaccuracy of one part in ten thousand are preferably employed in theoscillator.

Another simple, though not so effective method of tuning consists ofusinga dual channel amplifier to receive the standard frequency andobserved frequency, respectively, and then observe the interferencebeats, caused by-these two frequencies when close to unison, in a meter61 connected between the output of the amplifier 85 and the tuning forkamplifier apparatus II. This meter 51 may be coupled to the amplifierGland the tuning fork amplifier H through a suitable transformer havingone or more primary wind ings and/or through a suitable rectifier orrectifiers of the dry disc type for example. Very accurate results canbe obtained 'by this method, but it has the same shortcoming as thehuman ear, namely, that it isnt easy to tell when the observedfrequencyis high or low with respect to the standard. This difliculty,however, can be over-come by the use of a properly polarized bridgecircuit connected to the meter; and while this method is good for rapidproduction, the cathode ray oscillograph method has the advantage thatit also portrays the wave form under observation as well as indicatingits relative frequency.

While in the above specifications I have confined my remarks principallyto tubular chimes, the same method can be applied to such instrumentsas-bells, bars, tuned rods, and other percussion instruments.

In addition to the uses of the carillon I have described as an outdoorinstrument, the same to take the place of manually operated chimes theopposite direction. The amount of drift per second is equal to thedifference in frequencies -per'second. In my method of tuning I use'bothof these systemsthe latter for the more rough tuning and the former forvery close adjustment.

In some instances where I desire to emphasize certain harmonics I mayprovide frequency selective filters or networks, such as, bandpassfilwhen desired.

What I claim is as follows:

1. In a chime carillon, a chime, a striker for said chime, a solenoidfor actuating said striker, a double touch key having means for closingthe circuit of said solenoid when partially depressed, electricalpick-up means positioned on said chime to pick up vibrationscorresponding to the fundamental tone of said chime, amplifier means,means on said key for closing the circuit between said magnetie pick-upand said amplifier means when said key is further depressed, additionalpick-up means for picking up acoustic vibrations from said chime, andconnections between said additional pick-up means and said amplifiermeans.

2. In a chime carillon, a chime, a striker, a vibration pick-up forsaid'chime, an amplifier, connections for connecting said pick-up tosaid amplifier, said connections including a condenser, connections forcharging said condenser, and connections for applying a grid biasingpotential to said amplifier from said condenser after said chime Lsstruck and said first .mentioned connections are opened for maintainingsaid amplifier operative until the charge of said condenser isdissipated so that the amplification of said pick-up output is notsharply interrupted.

. 3. In a chime carillon, a chime, means for setting said chime intovibration, a vibration pick-up for said chime, an amplifier connected tosaid vibration pick-up to amplify the output thereof, switch means forconnecting said vibration pick-up to said amplifier substantially whensaid chime is set into vibration, and time delay means consisting of acondenser connected across said switch, means for charging saidcondenser when said switch is closed, the time delay action of said timedelay means being initiated by the opening of said switch so that thecharge of said condenser is applied to an electrode of said amplifierand maintains said amplifier operative 'untll said charge is dissipatedgradually.

4. In a chime carillon, a chime, means for setting said chime intovibration, a vibration pick-up for said chime, an amplifier connected tosaid vibration pick-up to amplify the output thereof, switch means forconnecting said vibration pick-up to said amplifier substantially whensaid chime is set into vibration, and time delay means connected to saidswitch, said time delay means including a condenser, means for chargingsaid condenser when said switch is closed and for applying the charge ofsaid condenser to a grid of said amplifier to initiate the time delayaction when said switch is opened.

' 5. In a chime carillon, a chime, a striker for said chime, a solenoidfor actuating said striker,

a double touch key having means for closing the circuit of said solenoidwhen only partially depressed, pick-up means positioned to pick-upvibrations of said chime, amplifier means and means on said key forclosing the circuit between said P ck-up and said amplifier means whensaid key is further depressed so that the circuit of said pick-up andsaid amplifier means is not energized immediately upon the striking ofsaid chime by said striker.

6. In a carillon a plurality of vibrating members for producing thetones of a musical scale, each of said members being adapted to producea number of substantially harmonically related tones, strikers for saidmembers, a double touch keyboard, each of the keys of said keyboardhaving two sets of contacts, one of said sets of contacts being closedwhen the key is partially depressed and the other being closed when thekey is further depressed, solenoids for controlling said strikersconnected to the contacts of said keyboard that are closed when the keysthereof are only partially depressed, solenoid controlled dampers forsaidvibrating members connected to said striker solenoids, an electricpick-up for each of selected ones of said plurality of memberspositioned to pick up the deep bell-like tones of said vibratingmembers, amplifying means, connections for connecting selected ones ofthe other of said sets of contacts of said keys to the input of saidamplifying means and to selected ones of said electric pick-ups forconnecting these electric pick-ups to said amplifying means when saidkeysv are further depressed, microphone means positioned to receiveacoustic vibrations from saidplurallty of members. means for connectingsaid microphone means to said amplivibrate and even after said electricpick-ups stop picking up said vibrations.

7. In a carillon a plurality of members for producing the tones of amusical scale, each of said members being adapted to produce a number ofsubstantially harmonically related tones, an electric pick-up for eachof selected ones of said plurality of members, amplifying means,connections for connecting said amplifying means to said electricpick-ups, microphone means positioned to receive acoustic vibrationsfrom said plurality of members, means for connecting said microphonemeans to said amplifying means, and electrical damping means connectedbetween said electric pick-ups and said amplifying means for preventingthe abrupt stopping of the picking up and amplifying of the deepbell-like tone vibrations picked up by said electricpickups, saidmicrophone means being continuously connected to said amplifying meansso that said microphone picks up vibrations of said chime member as longas said member vibrates and even aftersaid electric pick-ups stoppicking up said vibrations.

8. In a carillon a plurality of members for producing the tones of amusical scale, each of said members being adapted to produce a number ofsubstantially harmonically related tones, strikers and dampers for saidmembers, a double touch keyboard, each of the keys of said keyboardhaving two sets of contacts, one of said sets of contacts being closedwhen the key is partially depressed and the other being closed when thekey is further depressed, solenoids for controlling said strikers anddampers connected to the contacts of said keyboard that are closed whenthe keys thereof are only partially depressed, an electric pick-up foreach of selected ones of said plurality of members, amplifying means,connections for connecting selected ones of the other of said sets ofcontacts of said keys to the input of said amplifying means and toselected ones of said electric pick-ups for connecting these electricpickups to'said amplifying means when said keys are further depressed,microphone means positioned to receive acoustic vibrations from saidplurality of :members, means for connecting said microphone means tosaid amplifying means, and electrical damping means connected betweensaid electric pick-ups and said amplifying means for preventing theabrupt stopping of the picking up and amplifying of the deep bell-liketone vibrations picked up by said electric pick-ups, said microphonemeans being continuously connected to said amplifying means so that saidmicro-.

phone picks up vibrations as long as one of said keys is kept partiallydepressed to withhold the corresponding damper and the correspondingchime member vibrates and even after said elec tric pick-ups stoppicking up said vibrations.

9. In a carillon a plurality of members for producing the tones of amusical scale, each of said members being adapted to produce a number ofsubstantially harmonically related tones, solenoid actuated dampers forsaid plurality of tone producing members,'a double touch keyboard, eachof the keys of said keyboard having two sets of contacts, one of saidsets of contacts being closed when the key is partially depressed andthe other 1 beingclosed when the key is further depressed,

connections for connecting said damper solenoids to the contacts of saidkeyboard that are closed when the keys thereof are only partiallydepressed, an electric pick-up for each of selected ones of saidplurality of members, amplifying means connections for connectingselected ones of the other of said sets of contacts of said keys to theinput of said amplifying means and to selected ones of said electricpick-ups for connecting these electric pick-ups to said amplifying meanswhen said keys are further depressed, microphone means positioned toreceive acoustic a solenoid consisting of a plurality of turns ofvibrations from said plurality of members, means I vibrations.

10. In a carillon, a member for producing tones, an elongated strikerhaving a body of magnetic material for striking and setting said memberinto vibration, an elongated race of graphited material for saidelongated striker, a retaining member of non-magnetic materialsurrounding said elongated race, a solenoid consistingof a plurality ofturns of wire surrounding said retaining member of non-magneticmaterial, means for normallyholding the magnetic body of said strikersubstantially ofi center in said solenoid so that application of anelectric current to said solenoid will produce a -magnetic field thereinprojecting said striker against said first member, said race ofgraphited material being formed of such shape that it presents arelatively friction free, non-gripping, highly wear-resistant surface tosaid striker whereby quiet, uniform striker operation over long periodsof time is obtained;

11. In a carillon, a member for producing tones, an elongated strikerhaving a body of magnetic material for striking and setting said memberinto vibration, an elongated race of graphited material for saidelongated striker, a retaining member of non-magnetic materialsurrounding said elongated race, a solenoid consisting of a plurality ofturns of wire surrounding said retaining member of non-magneticmaterial, a U-shaped yoke of magnetic material with the ends thereofadjacent the ends of said solenoid, said retaining member extending intoholes formed into said yoke ends for supporting said solenoidsubstantially in said yoke, means for normally holding the magnetic bodyof said striker substantially oil center in said solenoid so thatapplication of an electric current to said solenoid will produce amagnetic field therein projecting said striker against said firstmember, said race of graphited material being formed of such shape thatit Presents a relatively friction free, non-gripping, highlywear-resistant surface to said striker whereby quiet, uniform strikeroperation is obtained over long periods of time.

12. In a carillon, a member for producing tones, an elongated strikerhaving a body of magnetic material for striking and setting said memberinto vibration, a tube of substantially non-magnetic material fornormally housing said striker,

wire surrounding said tube of non-magnetic material, a surface ofgraphited material between said striker and said tube of non-magneticmaterial, means for normally holding the ma netic body of said strikersubstantially off center in said solenoid so that applicationof anelectric current to said solenoid will produce a magnetic field thereinprojecting said striker against 'said first member, said surface ofgraphited material being of such shape and positioned between saidstriker and said tube that said striker slides into and out of said tubein a quiet relatively friction free, non-gripping manner so thatuniform, wear resistant operation is obtained over long periods of time.

13. In a carillon, a member for producing tones, an elongated strikerhaving a body of magnetic material for striking and settting said memberinto vibration, a tube of substantially non-magnetic material fornormally housing said striker, a solenoid consisting of a plurality ofturns of wire surrounding said tube of non-magnetic material, a surfaceof graphited material between said striker and said tube, said tubeextending well beyond one end of said solenoid, a U-shaped yoke ofmagnetic material with the ends thereof adjacent the ends of saidsolenoid, said tube extending into holes formed into said yoke ends forsupporting said solenoid substantially insaid yoke, spring means fornormally holding the magnetic body of said striker substantially ofl.

center in said solenoid so that application of an electric current tosaid solenoid will produce a' Y so that said spring is stretched whensaid striker is projected from said tube and functions to guide thestriker back into said tube after striking said first member, saidsurface of graphited material being of such shape and positioned-betweensaid striker and said tube that said striker slides into and out of saidtube in a quiet relatively friction free, non-gripping manner so thatuniform, wear resistant operation is obtained over long periods of time.

14. In a chime carillon and similar musical instruments, -a vibratingmember, a vibration pickup device, an amplifier, a switch for connectingsaid pick-up device and said amplifier for amplifying the output of saiddevice, an electrical storage device, means for charging said storagedevice when said switch is closed and connections between said storagedeviceand said amplifier to gradually permit said amplifier to becomeinoperative as the charge of said storage device is dissipated when saidswitch is open.

EDWARD V. SUNDT.,

